Study reveals how to stop youngsters eating unhealthy snacks

Psychologists have successfully trialled a new intervention which makes schoolchildren cut down on unhealthy snacking. 

Researchers from Staffordshire University found that secondary school pupils often overestimate how much unhealthy snacking goes on among their peers and such misperceptions make them more likely to eat unhealthy snacks themselves.

Sian Calvert, who led the research across a series of studies, said: “In focus groups with 11 to 13-year-olds conducted prior to the intervention, we found they knew what healthy dietary behaviours were, and the short-term and long-term effects, but didn’t always practice these behaviours.

“Students were regularly eating unhealthy snacks which seemingly influenced their regular meal consumption – they were skipping meals because of the snacking. The focus group discussions also indicated that in this age group peers were an important influence on their dietary behaviours.”

Public Health England has warned that the regular consumption of unhealthy snacks is contributing to adolescents being overweight or obese, increasing the likelihood of long-term ill-health.

NHS data also indicate that obesity is strongly related to socioeconomic status, with children living in the most deprived areas of the United Kingdom twice as likely to be overweight or obese compared to those living in the least deprived areas.

To help address this, Sian and colleagues developed a school-based intervention using the Social Norms Approach (SNA) – a technique that works by correcting misperceptions about others’ behaviour.

The study was conducted with Staffordshire University colleagues, Dr Rachel Povey, Associate Professor of Health Psychology, and Emeritus Professor David Clark-Carter alongside Dr Rob Dempsey from Manchester Metropolitan University.

Dr Rachel Povey explained: “Adolescence is an important time for rapid growth and development, but it is also when children gain more control over their own diet and often establish unhealthy eating habits. At secondary school, students might stop at a shop on the walk to school, or buy snacks on their way home, so they have access to a wider range of food.”

The study involved more than 150 Year 7 pupils, aged 11-12 years old, from two schools located in Greater Manchester and Staffordshire.

Both schools received healthy eating information, while students in the SNA intervention also received feedback correcting their misperceptions of peers’ snacking behaviour. This was presented through an interactive poster-making session as suggested by an advisory panel of slightly older Year 8 students.

Following the intervention, participants in the SNA intervention consumed significantly fewer unhealthy snacks, had more accurate perceptions about other students’ behaviours and had more negative attitudes towards unhealthy snacking.

Sian said: “Our results are important, as it is recommended that adolescents eat a healthy balanced diet, only eat unhealthy snack foods occasionally, and in small amounts, to support normal development and to reduce the likelihood of long-term ill-health.

“This study indicates that the Social Norms Approach is a feasible strategy to use in schools to promote healthy eating behaviours at an impressionable age and could be used in future, which is really promising.”

Read the full paper:

An in-school social norms approach intervention for reducing unhealthy snacking behaviours amongst 11–12-year-olds Calvert, S.M., Dempsey, R.C., Povey, R. and Clark-Carter, D. (2022) British Journal of Health Psychology